Two dimensional sweep circuit



y 5, 1964 B. DERADOORIAN 3,132,282

TWO DIMENSIONAL SWEEP cmcun" Filed Dec. 14, 1959 s4 \1 so 4 I I I? new CKT I I VOLTAGE 33 g SOURCE fi:F 2| VOLTAGE '3 SOURCE 22 25 28 N:

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- R c v R- I VOLTAGE C SOURCE INVENTOR. H G, 4. BAG DASAR DERADOORIAN ATTORNEY electron stream. a V p a These and other objects will become more apparent United States PatentOfiFice 3,132,282 Patented May 5, 1964 3,132,282 1 TWO DIWNSIQNAL SWEEP CIRCUIT Bagdasar Deradoorian, Detroit, Mich, assignor to The Y {Bendix Corporation, a corporation of Delaware Filed Dec. 14, 1959, Ser. No. 859,472

. 11 Claims. (Cl. 315-23) This invention pertains to a two dimensional sweep circuit and, more particularly, to a simplified sweep circuit v usable in a thin television tube and the like. 7 It is an object of this invention to provide a two dimensional sweep circuit for causing an electron beam to be 1 to be repelled in a direction normal to the plate at various points depending on the value of the varying voltage.

It is another object of this invention toprovide atelevision tube wherein a stream of electrons from an electron gun'is directed along a resistive strip which has a variable potential placed thereacross with the stream being repelled in a direction normal to the strip at various points along the strip as the potential is varied, with the repelled electron stream being moved along one dimensionof and parallel to a resistive plate having a variable voltage placed across the second dimension of the plate so that the electron stream is repelled at various points along the second dimension of the plate as the voltage is varied, and with a phosphor screen being placed parallel and adjacent to the resist've plate to receive the repelled when a preferred embodiment of this invention is con: sidered in connection with the drawings in which:

FIGURE 1 is an elevational view, partly broken away, of the schematic diagram of a'preferred embodimentof this invention;

' FIGURE 2 isan end view of the embodiment shownin FIGURE 1;:

FIGURE 3 -is a graphical illustration of the manner in which voltage .is varied along a resistive length; and

FIGURE 4 is a schematic diagram of a second embodiment of this invention. l

It has been an'object for a number of. years of the electronics industry and especially the television develop ment'and manufacturingindustries, to provide a thin two dimensional sweep tube. Tubes of this nature have been 7 developed but, due to their complexity and other-diffil: "culties'a are not in common use. This invention provides airelatively simple tube. construction of very narrow dimensions which can provide' the sweep necessary along.

' a phosphor screen of a television tube. Thisis donewith.

' the voltage is applied.

only two electrical connections to a vertical deflection: plate which is manufactured of a resistive material so that a. potential drop is developed thefreacross whena voltage applied thereto. An electron stream, such as emanates from anelectron gun in a television tube is fcaused to.

,f'move along the plate, and by varying the voltage across. the platelthe stream is repelled in a direction perpendic: ular'; fromthe plate along the dimension across which In FIGURE 1 is an electron gun 20 emitting a stream of electronsiZIL which vary in intensity according to pic- '.-ture-'-informa-tion received from a television transmitting station by a receiver 19. The stream 21 is directed along a stripl22 which may be of glass or Bakelite and which has a resistive coating 23 of predetermined ohmage on one surface thereof. A coating of this nature may be obtained by spraying an antimony and tin solution on the glass surface in proportions and thicknesscorresponding to the desired resistance. Between ends 24 and 25 of strip 23 is placed a variable voltage in'the form of a sawtooth pulse 26 produced by source 28. v

,The stream 21 is'repelledfin a direction normal from the strip 22 when any point of 'the strip reaches a voltage E (FIGURE 3). By applying the sawtooth pulse 26 at end 25, the potential at end 25 is gradually decreased due to the decreasing slope of the sawtooth pulse. When the voltage at end 25 of strip 22 is equal to E the electron stream will be repelled from the strip ,at point 25; as the voltage at end 25 decreases, the stream 21 will be repelled at earlier points along the strip. This is so since, when the voltage at end 25 is decreased to E the point at which the stream 21 will be repelled from strip 22 will be P that point where the potential gradient line of voltage E crosses theE line. 7 As the voltage is further decreased to E the electron stream 21 will be diverted at point P of strip 22 since it is at this point that the potential gradient line for voltage E crosses the repelling voltage line. of E In this manner the electron stream 21 is repelled from strip 22 with the point of repelling moving in a right-to-left direction with a rate depending on the slope of pulse 26. Placed in perpendicular relation to horizontal strip 22 is a vertical plate 30 which also may be of glass, Bakelite, or a similar insulative material coated with a resistive material 31 of predetermined ohmage and which receives a pulse 34 from source 29 which is connected at the top 32 and bottom 33 of the plate 30 so that a potential drop is formed along the vertical dimension of plate 30. The pulses 26 are much more frequentthan the pulses 34 and when applied to the plate 30 each pulse causes the electron stream 21 '(FIGURE 2) to be repelled from the" plate 30 at points along the plate which move from top to bottom in much the similar manner that the stream is repelled at various points from strip 22. e

Parallel to and spaced adjacent to plate 30 is'a phosphor screen 40 which receives the repelled electrons from plate 30. Screen 40 has a coating of a material which will 7 be modulated in accordance with picture or 'otherinforma- 9 tion. The stream is directed along strip 22 which has a resistive coating 23 along the surface thereof and which has connected atends 24 and 25 a yariablevoltage source in the form ofa negative sawtooth pulse," The pulse is applied to end 25 of the strip and as end 25 becomes increasingly negative, electron stream 21 will be repelled from the strip at points increasingly distant from end 25.

This is so becausea-potential gradient is formed along strip 22 due to current flow in'the resistive'coating. In,

this manner 'the stream 21' moves from the right side of plate 30 tothe left side, once for every sawtooth pulse.

While the stream is moving across plate30, a series of negative sawtooth pulses is applied between the. top edge .32 of plate 30 and the bottom edge 33; Forevery negative sawtooth pulse that is"applied between edges 32, 33 the electronstream is repelled along a line from the top edge to the bottom edge of the plate 30 and impinges upon a phosphor screen .40. The pulses applied to the strip 22 are frequent enough so that the picture formed on screen 40 appears continuous to the human eye.

With this embodiment only two electrical connections are necessary to plate 35) and strip 22 with corresponding reduction in circuit components and complexities. 7

Other means may be. utilized to cause stream 21 to move along the horizontal dimension of plate 39. These means could include a pair of deflection plates between which the stream passes and to which a variable voltage is applied to influence the stream through an arcuate path as illustrated in FIGURE 4. In FIGURE 4a sawtoo h voltage pulse is applied by source 45 between plates 42, 44 which are placed adjacent the mouth of an electron gun 47, energized by receiver circuit 46 which is similar to receiver circuit 19 in FIGURE 1, and influence the electron stream 48 in an arcuate path to move across plate 30A which is pulsed in the same manner as plate 30 in the previous embodiment to repel the electron stream into a phosphor stream. Voltage source 28a provides asawtooth voltage across plate 30awhich issimilar to the voltage placed across plate 36 in FIGURE 1.

Although this invention has been disclosed and illus-. trated with reference to particular applications, the principles involved are susceptible of numerous other ap' plications which will be apparent to persons skilled in the art. The invention is, therefore, to be limited only as indicated by the scope of the appended claims.

Having thus described my invention, I claim: 1(Television tube sweep circuit comprising an elec tron gun for emitting a modulated electron stream in a first direction, a strip having a coating of resistive material of predetermined ohrnage, said stream being directed along'said strip, means for applying a sawtooth voltage acrosssaid resistive coating causing a corresponding cur-. rent to flow therethrough' and progressively lower the potential along said coating to progressively repel said stream in a second direction from said coating in a plane substantially perpendicular to' said coating, a plate having a resistive coating of predetermined ohmage being placed in a plane adjacent and substantially parallel to the plane.

of said stream, means for applying a sawtooth voltage acrosssaid. plate in a direction substantially parallel to.

the said second'direction of said stream to progressively. repel the stream from said plate coating, a phosphor screen being placed in a plane adjacent and substantially parallel to said plate and being located substantially'in 7 front. of said resistive coating in order to receive said repelled stream.

2. Two dimensional sweep means comprising means for emitting a, charged particle stream; a plate means having a-resistive surface,

resistivesurface of said second plate means, providing a predetermined voltage drop and voltage gradicut across said resistive surface of said second plate means,

so thatthe stream moving across said resistive surface is deflected in a direction having a normal component to said second plate means and in a direction which causes said stream to move across and have asubstantial component parallel to said first mentioned plate means, a

said stream being deflected at points along said resistive surface of said second plate means which vary in a manner corresponding to the manner in which 'the voltage varies across the resistive surface of said second plate means; I

4. The apparatus of claim 3 with means to cycle the voltage placed across the resistive surface of said first mentioned plate means in a predetermined ratio to the number of times the voltage placed across the resistive surface of said second plate means is cycled.

5. The apparatus of claim 4 with a. V

phosphor screen being placed adjacent and parallel to said first mentioned plate means,

said charged particle stream being directed between said phosphor screen and said first mentioned plate means,

said charged particle stream being repelled from said .first mentioned plate means towards said phosphor screen toimpinge upon said phosphor screen.

6. The apparatus of claim 5 with said charged particle stream emitting means being an electron gunifor modulating the intensity of said i stream according to received information.

7.- Thetwo dimensional sweep means of claim 2 where said means for causing said stream to'rnove along a, portion of said plate meanscomprises an electrode located on each side of said electron stream, means to apply voltages to said electrodes to cause said stream to recipmeans for causing said stream to move across at least a portion of said plate means,

'variable voltage means being placed alonga portion of'the resistive surface of said plate means thereby causing a corresponding current flow in said resistive surface of said plate means providing a predeter-' mined potential drop and voltage gradient across said resistive surface, I

, so that the stream.moving across said resistive surface is deflected in a direction having a normal component to said plat'e'means;

said stream being deflected at points along saidresis tive surface which vary ina manner corresponding to manner'in which the voltage varies across said resistive surface. a 3. The apparatus of claim ing said stream to. move'across'at least a portion of said plate means comprising,

a second plate means having a resistive surface, said second plate means being placed adjacent toedge I of said first mentioned plate means,

variable voltage means being placed of said resistivesurface of said second'plate'means, thereby causing a corresponding current flow in'said' 2 with'the means for caus along a portion rocate'between said electrodes in a plane substantially parallel to said plate means. a

8. Television tube sweepcircuit comprising an electron gun for emitting a modulated electron'stream, an:

electrode beingplaced on'each side'of said stream, voltage means being connected to said electrodes to cause said stream to reciprocate in a plane having a substantial component parallel to said electrodeaa plate having a resistive coating of predetermined ohmage being placed in a plane adjacent and substantially parallel to said planev of said stream reciprocation, means for applying a sawtooth voltage across said plate in a direction having a substantial component parallel to a line perpendicular to a line connecting said electrodes to progressively repel the stream from said plate coating, 2. phosphor screen being placed in a plane adjacent and substantially parallel to said plate and being located substantially in front of said resistive, coating in order to receive said repelled V stream.

9. Two dimensional sweep means comprising means for emitting a charged particle stream, a resistive material 7 being of acontinuous structure over the area to be traversed by the charged particle stream, means forcausing said stream. tomove in a direction having a substantial component which is parallel to' the faceof said continuous resistive material, said'stream'being.substantially parallel to agiven line on said resistive material as it moves across said resistive material, cyclic voltage means being connected 'to said resistive material at two contact points which are on a linewhich has a substantial component parallel to said givenline on said resistive material, said cyclic voltage means causing a changing voltage gradient corresponding to each voltagecycle so that said stream in moving across said. resistive material 'is repelled from said resistive material at various points along the stream path corresponding to said voltage gradient.

10, The two dimensional sweep means of claim 9 wherein said means for causing said stream to move substantially parallel to the face of said resistive material 3 comprises a continuousresistive strip of predetermined ohmage placed adjacent to an edge of said resistive material, said strip being substantially perpendicular to a line passing through said contact points of said cyclic voltage means, voltage means for applying acyclic voltage across the length of said strip being connected to the ends of said strip, said charged particle stream being directed by said emitting means in a direction having a substantial component parallel to said strip adjacent to said resistive material, said stream being repelled from said strip at succeeding points along said strip depending upon the'voltage gradient determined by the cyclic volt- 1 age applied to said strip.

6 11. The two dimensional sweep means of claim 9 where said voltagemeans provides a plurality of voltage cycles each time said stream moves adjacent to and across the face of said resistive material, so that said stream is repelled at a predetermined number of points from said resistive material.

References Cited in the file of this patent UNITED STATES PATENTS 2,880,365 Law 'Mar. 31. 

1. TELEVISION TUBE SWEEP CIRCUIT COMPRISING AN ELECTRON GUN FOR EMITTING A MODULATED ELECTRON STREAM IN A FIRST DIRECTION, A STRIP HAVING A COATING OF RESISTIVE MATERIAL OF PREDETERMINED OHMAGE, SAID STREAM BEING DIRECTED ALONG SAID STRIP, MEANS FOR APPLYING A SAWTOOTH VOLTAGE ACROSS SAID RESISTIVE COATING CAUSING A CORRESPONDING CURRENT TO FLOW THERETHROUGH AND PROGRESSIVELY LOWER THE POTENTIAL ALONG SAID COATING TO PROGRESSIVELY REPEL SAID STREAM IN A SECOND DIRECTION FROM SAID COATING IN A PLANE SUBSTANTIALLY PERPENDICULAR TO SAID COATING, A PLATE HAVING A RESISTIVE COATING OF PREDETERMINED OHMAGE BEING PLACED IN A PLANE ADJACENT AND SUBSTANTIALLY PARALLEL TO THE PLANE OF SAID STREAM, MEANS FOR APPLYING A SAWTOOTH VOLTAGE ACROSS SAID PLATE IN A DIRECTION SUBSTANTIALLY PARALLEL TO THE SAID SECOND DIRECTION OF SAID STREAM TO PROGRESSIVELY REPEL THE STREAM FROM SAID PLATE COATING, A PHOSPHOR SCREEN BEING PLACED IN A PLANE ADJACENT AND SUBSTANTIALLY PARALLEL TO SAID PLATE AND BEING LOCATED SUBSTANTIALLY IN FRONT OF SAID RESISTIVE COATING IN ORDER TO RECEIVE SAID REPELLED STREAM. 